关键词: 苔藓植物, 环境梯度, 预测变量, 随机森林, 指示种分析

Abstract: Bryophytes, as the most primitive higher plants, are small in individuals and often have large cushioned cluster communities, which are extremely sensitive to environment. In order to investigate the relationship between the surface bryophytes of subtropical forest and various habitats, and study the habitat-indicative role of bryophytes, data collected from 6 hm2 permanent plots in Guangdong Kanghe Provincial Nature Reserve were analyzed. We used Random forest analysis was used to test the predictive importance of different habitat factors on bryophyte, and used indicator species analysis was used to reveal the indicative species under different habitat gradients. The results showed that convexity and potential direct incident radiation were of high importance to the cover, richness, Simpson Index, evenness and Berger-Parker dominance of Moss and Liverwort, which indicated that convexity and potential direct incident radiation had great influence on bryophytes and were important environmental factors to limit the growth of bryophytes. The habitat factors such as slope and elevation also had different effects on the diversity index of bryophytes, which showed that the diversity pattern of bryophytes was not affected by a single factor, but influenced by many factors. The indicator species analysis showed that there were differences in the indicative species of bryophytes under different habitat gradients, and some bryophytes were able to indicate different habitat conditions at the same time. Pseudotaxiphyllum pohliaecarpum had significant indicative effect on the 2nd elevational gradient, the 3rd slope calss and the 1th convexity gradient, with wide ecological amplitude. Rhynchostegium pallidifolium had significant indication effect on the 1th elevational gradient, sunny aspect and 2nd convexity gradient, with high ecological amplitude and strong adaptability.

Key words: bryophyte, environmental gradient, predictor variable, random forest, indicator species analysis